Software-Defined Radar for Medical Imaging

A low-cost reconfigurable microwave transceiver using software-defined radar is proposed for medical imaging. The device, which uses generic software-defined radio (SDR) technology, paves the way to replace the costly and bulky vector network analyzer currently used in the research of microwave-based medical imaging systems. In this paper, calibration techniques are presented to enable the use of SDR technology in a biomedical imaging system. With the aid of an RF circulator, a virtual 1-GHz-wide pulse is generated by coherently adding multiple frequency spectrums together. To verify the proposed system for medical imaging, experiments are conducted using a circular scanning system and directional antenna. The system successfully detects small targets embedded in a liquid emulating the average properties of different human tissues.